sigma-rs: A Modular Approach for Keyed-Verification Anonymous Credentials

We introduce a new software stack in Rust aimed at simplifying constructions and deployments of protocols based on modern anonymous credential systems.

The stack, called SIGMA-RS, through its layered design, abstracts cryptographic complexity while remaining flexible enough to support a range of credential schemes, proofs, and access policies. It emphasizes misuse resistance via type safety, domain separation, and prover-state discipline, and supports side-channel-aware constant-time strategies.

We evaluate practicality through re-implementations of Tor's Lox bridge distribution protocols and of user authentication in the Open Observatory for Network Interference.